Kate 3F is a control car (a unpowered car with a cab for controlling locomotives). A freelance model based on Kate 1 http://shpws.me/MfqP and Kate 2 http://shpws.me/MfQA .
See Kate 2 for a fictional backstory, designed to be used with 2 or 3 Kate 2 locomotive, this control car is fitted with dynamic brakes, a small engine (for power and air) and a freight area for less than a car load traffic (parcels, mail, so on).
Like Kate 2, due to the size it may fit well on an OO9 layout.
Fits the Kato 11-105, 11-106, or 11-107 chassis.
Not intended to be run with a motored chassis (with you want to go right ahead, it is up to you). Recommendation: If the builder carefully removes the motor and gearing from a new or poorly performing Kato chassis leave the power pickups and rails in place. Jumpers can be fitted between the control car and locomotives, increasing the pick-up area by another 4 wheels. A good socket arrangement can be made by using small Socket to Socket Jumper Leads designed for use with Breadboards, Arduino, or electronics prototyping that can be sourced through electronics stores or ebay. For example (not an endorsement or recommendation) 150mm Socket to Socket Jumper Leads - 40 Piece
Use one wire cut into two (for locomotives use two wires cut into four, that is 4 sockets with a length of wire attached), cut to the required length (to reach from body to power rail or longer), connect the non-plug end to the power rail, drill small hole in body and affix plug in it, repeat for the other power rail. Connection between models can be easily achieved by using suitable coloured (grey is good) solid cored breadboard hook-up wire or similar, it is flexible and also sturdy enough to stay in place while running. Cut a short length of wire, long enough to bridge the gap and also hang down but not long enough to interfere with the coupler or track, strip about 6mm (about 1/4 of an inch) of insulation from each end and bend 45 to 90 degrees where it meets the insulation, the exposed core is the pin for the socket and the bend is to provide a realistic sag to the wire. Placement or removal is made easier with the use of tweezers while the units are coupled on the rails (power off). Strong recommendation that your track should be protected by a fuse or breaker (it should be if you value your layout, and fuses are cheap) as there is a very slight chance one could fall out unnoticed and bridge the rails.